Refactor sinon helper to make it easier to use.

remoting/webapp/unittests/test_start.js

Index: remoting/webapp/unittests/test_start.js
diff --git a/remoting/webapp/unittests/test_start.js b/remoting/webapp/unittests/test_start.js
deleted file mode 100644
index 8159ce7b6745d8c2226ddda58d156d637985bde2..0000000000000000000000000000000000000000
--- a/remoting/webapp/unittests/test_start.js
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Global test setup.
-// This code is run before each test in every module.
-
-QUnit.testStart(
-    /** @param {{module:string, name:string}} details */
-    function(details) {
-      sinonHelpers.reset();
-    });